Overall:
Excellent apartment, responsive and caring host, and above average facilities and facility management.
Apartment:
Excellent facilities and a comfortable room with a great view of the city skyline. Two air conditioners that work great, good washing machine and a smart TV (YouTube, phone streaming, etc.), comfortable bed and pillow selection. The whole place was very comfortable and well kept. Nice couch, an electric stove, electric kettle, full sized fridge/freezer.
Overall the room was quite comfortable. There's a sliding glass door between the bedroom and the living room area, so it can feel like separate rooms, or one large room. The bathroom was great, shower water got hot, no problems with water pressure.
Host:
Our host was caring and responsive. He brought us everything we asked for. Our rice cooker broke, and he gave us a new one that day. Our air conditioner had issues, and someone fixed it within the hour. He brought more pillows, soap, etc. Just overall helpful and responsive. I was writing in Chinese, so you may want to use Google translate to write in Chinese.
Facilities:
The facilities were my favorite part of this apartment. They're a minute from the apartment building and include an infinity pool, sauna, gym with benches, dumbbells, cable weighted machines, smith press, treadmills, bikes, etc. There's also a work room, library, lounges outside and by the pool, a BBQ area (BBQ out of order March 2020), showers and 3 home theater rooms with big couches and large TVs.
Eco One has highly competent management. I stayed throughout the beginning of the COVID-19 scare, Feb to March 2020. There was always hand sanitizer available, and all staff wore masks. They were also very secure, with guards at the entrance monitoring the flow of vehicles into the compound.
Location:
15-20 minute walk to subway. If you're up for it, you can catch a motorcycle, should be cheap. A taxi to the subway is about 30 baht. This is the only negative I can come up with. We mostly took taxis around the city, and sometimes took the Subway, so it wasn't an issue for us. Always a taxi nearby. Popular road.
I will certainly return to this complex if I can when I come back to Bangkok. Highly recommended!